1. Field of the Invention
The present invention relates to a machine tool provided with a mist disposal structure capable of removing a mist in a machining area and preventing the mist from flowing into the interior of the machine tool.
2. Description of the Related Art
In a machine tool, high-accuracy straightness and high rotational accuracy can be realized by the use of an air bearing. The dustproof and waterproof performance of the conventional machine tool using the air bearing can be improved by the use of a labyrinth or several layers of non-contact bellows (e.g., Japanese Patent Application Laid-Open No. 2002-331439). Alternatively, a device for supplying clean air is disposed and used to increase the pressure in the machining area, thereby preventing penetration of a mist (e.g., Japanese Utility Mode Application Laid-Open No. 6-45315). In another arrangement, bearing air delivered from an air bearing is only discharged into the interior of a machine tool, and air supplied to the bearing is not utilized for dustproof and waterproof effects (e.g., Japanese Patent Application Laid-Open No. 2004-255494).
The machine tool that is provided with the air bearing must be improved in dustproof-waterproof performance without ruining its drive performance. The performance of a dustproof-waterproof structure of a drive section can be enhanced by using a non-contact labyrinth or the like. Since the non-contact structure inevitably involves voids, however, it is lower in dustproof-waterproof performance than any other bearing structure.
In high-speed rotation machining, such as milling, a cutting fluid is scattered as a mist in the machining area and sometimes may penetrate the interior of the machine tool through the labyrinth space of the drive section when it is applied to a tool and a workpiece.